1. Field of the Invention
The present invention pertains to a tandem agricultural implement hitch apparatus for towing at least two implements in a left or right echelon working formation and for towing the implements in an in-line tandem transport formation.
2. Background Art
Increases in the size and productivity of modern farms have gone hand in hand with the development of more powerful agricultural tractors with the capability of pulling larger arrangements of implements for greater ground coverage and fewer passes of the tractor over a field. However, the width of many existing gate openings and roadways, and the maximum legal width limitations for equipment transported on public roads necessarily limits the width of agricultural implements. Accordingly, there have been several efforts to develop implement hitch assemblies which are adapted for towing multiple implements in a configuration wherein the implements may be set laterally apart from each other for working the field and then brought into a generally in-line tandem arrangement for passing through gates and for transport over roadways.
Heretofore, efforts to develop suitable tandem implement hitches have resulted in fairly complex structures which are not particularly versatile and, for example, are adapted for towing two or more implements in either a left or a right echelon formation in a fixed working position of one implement with respect to the other. Reduction in the overall width of the hitch assembly has also been limited due to the configuration of some tandem hitches which do not sufficiently reduce the overall width of the vehicle assembly during road transport.
Moreover, most prior art hitch assemblies are adapted for towing two implements in one working position and are not adaptable for variations in implement width or for the type of implement being towed. Although implements such as planters are normally towed such that the implement tracks do not substantially overlap, in the application of certain other types of implements, it is desirable to have some overlap of the swath or track width of the implements. For example, in operation of implements such as disks, harrows, mowers and rakes, it is often desirable to overlap the track of the forward implement with the rearward implement to facilitate the operations being performed by the implements. It is also desirable in applications of tandem hitch arrangements to be able to form a left as well as a right echelon formation of the towed implements to facilitate working the implements on irregular shaped fields as well as sloped fields.
Accordingly, there has been a need for improvements in tandem hitch units to overcome the deficiencies of prior art apparatus, as noted herein, as well as to provide certain other improvements which are familiar to those skilled in the art. Several problems associated with prior art multiple hitch units have been overcome with a unique and relatively uncomplicated structure in accordance with the present invention.